U.S. patent application number 09/985570 was filed with the patent office on 2002-05-09 for information reproducing apparatus and information reproducing method.
This patent application is currently assigned to Pioneer Corporation. Invention is credited to Kono, Mutsumi, Obata, Hidehito, Shioya, Suguru.
Application Number | 20020054545 09/985570 |
Document ID | / |
Family ID | 18813148 |
Filed Date | 2002-05-09 |
United States Patent
Application |
20020054545 |
Kind Code |
A1 |
Shioya, Suguru ; et
al. |
May 9, 2002 |
Information reproducing apparatus and information reproducing
method
Abstract
A method and an apparatus are provided for reproducing data
recorded in a format different from CD, such as recorded in ISO9660
format. Specifically, TOC data is generated from the information of
a path table storing directory information of different stages (TOC
data generating section), and information recorded in a format
different from CD is reproduced in accordance with the TOC data
(information reproducing section).
Inventors: |
Shioya, Suguru; (Saitama
-Ken, JP) ; Obata, Hidehito; (Saitama-ken, JP)
; Kono, Mutsumi; (Saitama-ken, JP) |
Correspondence
Address: |
ARENT FOX KINTNER PLOTKIN & KAHN, PLLC
Suite 600
1050 Connecticut Avenue, N.W.
Washington
DC
20036-5339
US
|
Assignee: |
Pioneer Corporation
|
Family ID: |
18813148 |
Appl. No.: |
09/985570 |
Filed: |
November 5, 2001 |
Current U.S.
Class: |
369/30.11 ;
G9B/27.019; G9B/27.021; G9B/27.05 |
Current CPC
Class: |
G11B 27/105 20130101;
G11B 27/329 20130101; G11B 27/11 20130101; G11B 2220/2545 20130101;
G11B 2220/213 20130101 |
Class at
Publication: |
369/30.11 |
International
Class: |
G11B 007/085 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 6, 2000 |
JP |
2000-337831 |
Claims
What is claimed is:
1. An information reproducing apparatus for reproducing information
formed by a plurality of unit information recorded in a
hierarchical structure, said apparatus comprising: an absolute time
generation means for generating absolute time information from
position information of the unit information; and a reproducing
means for reproducing recorded information in accordance with the
absolute time information.
2. An information reproducing apparatus according to claim 1,
wherein the absolute time generation means is adapted to generate
absolute time information of the unit information, in accordance
with management information for managing position information of
the unit information.
3. An information reproducing apparatus according to claim 1,
wherein the unit information is data prescribed in accordance with
ISO9660, the absolute time information is time information
corresponding to TOC (Table Of Contents) prescribed in accordance
with Red Book.
4. An information reproducing method for reproducing information
formed by a plurality of u nit information recorded in a
hierarchical structure, said method comprising: generating absolute
time information from position information of the unit information;
and reproducing recorded information in accordance with the
absolute time information.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an information reproducing
apparatus and an information reproducing method for reproducing
data recorded in a format different from that used in CD (compact
disc).
[0003] The present application claims priority from Japanese
Application No. 2000-337831, the disclosure of which is
incorporated herein by reference for all purposes.
[0004] 2. Description of the Related Prior Art
[0005] There has been known a logical format such as ISO9660
logical file format which can be used for storing a hierarchical
structure file in CD-ROM. In detail, ISO9660 logical file format is
so formed that disc volume space has been divided into a plurality
of logical blocks which are provided with addresses indicated by a
series of continuous numbers starting from 0.
[0006] FIG. 7 is a block diagram showing the structure of a logical
file of ISO9660 format. In FIG. 7, reference numeral 21 is a volume
descriptor storing information concerning logical block address of
path table, size of path table, as well as logical block address of
root directory, and size of the root directory. In fact, the volume
descriptor 21 is fixed in its recording position and its size,
serving as a start point of an access to a hierarchical structure
file.
[0007] Reference numeral 22 is a path table storing information
concerning logical block addresses of all directories, sizes of the
all directories, as well as a hierarchical structure of the
directories. In fact, the path table 22 is variable in its
recording position and its size. Reference numeral 23 is a root
directory, 24 is a sub-directory, storing information concerning
(for example) sizes of files 30 . . . (which serves as unit
information existing under the sub-directory. Here, the directory
23 is also variable in its recording position and its size.
[0008] In detail, logical file structure of ISO9660 format is
characterized in that it has the path table 22 which is in fact an
address table storing directory information of various hierarchies,
rendering it possible to reduce the number of necessary accesses to
a desired file.
[0009] Here, the path table 22 is a table containing all directory
informations (name and position of each directory, parent
directory, all arranged in accordance with a preferential order
according to their width) and is for use in searching a directory
at a high speed. However, since CD-ROM is slow in seek operation,
when sub-directory is searched, a considerable amount of time is
necessary in searching (one by one) respective sub-directories
separately located in a usual file system. In practice, since the
path table usually has one to several sectors, it is allowed to
perform a high speed access by performing a constant caching.
[0010] For example, if there are directory hierarchies shown in
FIG. 8, the order of path table records will be like that shown in
FIG. 9. Here, the front head (No. 1) is constantly a root
directory. If a file named as /USR/TMP/README. TXT; 1 is to be
searched, an operation procedure will be as follows.
[0011] Namely, at first, a root directory is searched from a group
of path table records having a level 1. Here, the number is 1.
Then, in a group of path table records having a level 2, the number
1 is held as a parent (it is obvious that parent level 2 is root),
while a number for searching an identifier called USR is number 4.
Further, in a group of path table records having a level 3, number
4 is held as a parent, thereby searching for an identifier called
TMP. At this time, the number is 8.
[0012] Afterwards, from No. 8 path table record showing /USR/TMP, a
position storing the directory main body is obtained, thereby
reading out the directory main body. Then, TMP/README. TXT; 1 is
searched from a group of the read-out directory records.
[0013] In this way, directory searching can be accomplished only by
searching a path table from its front head, without having to
search each of sub-directories separately dispersed on a disc.
[0014] However, when MP3 data recorded in a format such as ISO9660
standard (which is different from that for use in CD) is to be
reproduced, and when there is an instruction for searching a song,
it is necessary to search out a corresponding address. In order to
do this, a conventional method is to assign and record the above
path table in specifically determined memory areas. Alternatively,
the contents of the path table are recorded in these areas only at
the time a song is to be searched.
[0015] However, in the above described prior art, since special
memory areas are required for storing path table, it is necessary
to have a relatively large memory capacity. On the other hand, if a
path table is recorded only at the time a song is searched, a
relatively long time is needed until a desired song can be searched
out. Besides, as to an operation for searching out a song in
accordance with a path table, such an operation is different from
CD in which a search is performed in accordance with TOC (Table Of
Contents). For this reason, when a software for controlling the
operation of a reproduction apparatus is prepared, it is also
necessary to prepare another software for searching out a song in
accordance with a path table. As a result, a large number of
man-hours are necessary and this becomes a large burden on soft
workers.
SUMMARY OF THE INVENTION
[0016] An object of the present invention is to provide a method of
and an apparatus for reproducing information, capable of generating
TOC data from path table, reproducing data recorded in a different
format from CD in accordance with TOC data, using a software
conventionally possessed by a CD player to perform program
reproduction and repetition reproduction.
[0017] According to the present invention, there is provided an
information reproducing apparatus for reproducing information
formed by a plurality of unit information recorded in a
hierarchical structure, said apparatus comprising an absolute time
generation means for generating absolute time information from
position information of the unit information; and a reproducing
means for reproducing recorded information in accordance with the
absolute time information.
[0018] In one aspect of the invention, the absolute time generation
means is adapted to generate absolute time information of the unit
information, in accordance with management information for managing
positional information of the unit information.
[0019] In another aspect of the invention, the unit information is
data prescribed in accordance with ISO9660, the absolute time
information is time information corresponding to TOC (Table Of
Contents) prescribed in accordance with Red Book.
[0020] Further, according to the present invention, there is
provided an information reproducing method for reproducing
information formed by a plurality of unit information recorded in a
hierarchical structure, said method comprising generating absolute
time information from position information of the unit information;
and reproducing recorded information in accordance with the
absolute time information.
[0021] With the use of the present invention, by preparing TOC data
(which is the same as CD) in accordance with data recorded in a
format different from CD, when song data recorded in ISO 9660
CD-ROM format is reproduced, since it is allowed to execute the
same functions as provided by CD player when performing program
reproduction and repetition reproduction, it is allowed to use the
software contained within a conventional CD player (without having
to modify the software to any extent). In this way, it is possible
to reduce man-hours for making new software, and to provide a user
with a convenience as if he or she is using a conventional CD.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] These and other objects and advantages of the present
invention will become clear from the following description with
reference to the accompanying drawings, wherein:
[0023] FIG. 1 is a block diagram showing an internal constitution
of an information reproducing apparatus formed according to the
present invention.
[0024] FIG. 2 is a flowchart showing an operation of an embodiment
of the present invention.
[0025] FIG. 3 is a flowchart showing another operation of the
embodiment of the present invention.
[0026] FIG. 4 is a flowchart showing a further operation of the
embodiment of the present invention.
[0027] FIGS. 5A and 5B are explanatory views showing data structure
of directory records for use in explaining an operation of the
embodiment of the present invention.
[0028] FIG. 6 is an explanatory view showing an example of a
conversion into TOC data, as well as an example of ISO9660
file.
[0029] FIG. 7 is an explanatory view indicating an example of
ISO9660 file shown in FIG. 6, explaining a concrete example of a
conversion into TOC data having a logical file structure and
recorded in ISO9660 format.
[0030] FIG. 8 is a view showing an example of directory
hierarchy.
[0031] FIG. 9 is used to show an example of a path table
record.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0032] FIG. 1 is a block diagram showing an internal structure of
an information reproducing apparatus formed according to the
present invention. Here, the information reproducing apparatus
comprises a TOC data generating section 11 and an information
reproducing section 12.
[0033] Actually, the TOC data generating section 11 also serves as
an absolute time generating means, and is capable of generating
pseudo TOC data in accordance with information recorded in a path
table storing directory information (recorded in ISO9660 format) of
various hierarchies. The information reproducing section 12 is
provided to reproduce data recorded using data compression
technology suitable for recording music contents represented by MP3
(MPG1: Moving Picture Experts Group 1, audio layer III ). In fact,
such data to be reproduced is that recorded in a format different
from CD-ROM and is reproduced in accordance with pseudo TOC data
generated by the TOC data generating section 11.
[0034] Specifically, the TOC data generating section 11 is formed
by using a program of a system controller contained within a CD
player, with CPU 12 reading and executing the program. The
information reproducing section 12 operates under the control of
the system controller to output (through a speaker) data formed by
decoding the data read from CD and processing the data in a D/A
converter. At this time, the program reproduction and repetition
reproduction are also performed, exhibiting the functions for use
in reproducing CD.
[0035] FIGS. 2-4 are flowcharts showing operations of the
reproducing apparatus of the present invention, indicating a first
main routine 1, a second main routine 2, and a sub-routine, all for
generating TOC data.
[0036] Next, detail description will be given to describe the
operations of the present embodiment, with reference to FIGS.
2-4.
[0037] At first, the TOC data generating section 11 operates to
initialize a song counter contained within the system controller,
thereby setting the counter at "0" (step S21). Then, PVD (Primary
Volume Descriptor) is read from CD-ROM storing song data in ISO9660
format. Within the Volume, system areas are recorded in addresses
"0000"h-"7FFF"h (0-15 sectors), while volume descriptors, path
table groups, directories and files are recorded in "8000"h-(16
sectors-). PVD is recorded in the areas of 16-17 sectors.
[0038] From the PVD obtained in the above, it is allowed to know
the position storing the path table, also to know the size of the
path table (step S23). Then, the position of the path table is
accessed and the above position data as well as size data are
read-in (step S24). Here, the path table is formed by preparing and
properly arranging path table records relating to all directories
within the volume.
[0039] In detail, the path table records are those storing the
positions of extents (front head address) covering paths extending
from a root directory to the respective directories as well as
related directories.
[0040] Then, position data containing directory records are
obtained from the path table records (step S25). In fact, using the
position information of the extents within the path table records,
it is allowed to know the position storing directory records
(serving as management information). Subsequently, directory
records are read-in (step S26). In practice, one sector (2048
bytes) of data is read-in.
[0041] Directory records are those storing flags indicating the
positions of directories or positions of extents of files (all
managed by directory records), also indicating whether the above
data is file information or directory information.
[0042] Then, MP3 file is searched out from a directory record (step
S27). Actually, file identifier information within the directory
record is referred to, thereby searching out an object whose
extender is "mp3". Afterwards, it is checked whether MP3 file has
been found or not (step S28). If MP3 file has been found, the
process goes to step S31 shown in FIG. 3. On the other hand, if the
MP3 file has not been found, the process goes to step S29, so as to
check whether there is a next path table record.
[0043] At this time, it is determined, from the path table read-in
at step S24, whether there is a next path table record. If there is
such a next path table record, the process goes to step S25. On the
other hand, if there is not such a next path table record, it is
determined that the disc does not contain MP3 file (step S30), so
that the process is terminated.
[0044] In a flow chart shown in FIG. 3, at first, it is determined
whether there is a directory record (step S31). Actually, it is
determined whether length information of directory record is "0" or
not. If the length is "0", it can be determined that there is no
directory record information. If the length is not "0", it can be
determined that such directory record information is existing, so
that the process goes to step S32. If not, the process goes to step
S39.
[0045] At step S32, it is determined whether the directory record
is a file information and such determination may be effected by
referring to a file flag within the directory record. If the
directory record is a file information, the process proceeds to
step S34. On the other hand, if the directory record is a directory
information, the process proceeds to step S33. At step S33, it is
determined whether the directory record information is "its own
directory". Actually, if a file/directory identifier within the
directory record is "00", it can be determined that the directory
record information is "its own directory".
[0046] In this way, if the directory record information is "its own
directory", the process goes to step S39. If not, the process goes
to step S38. Here, "its own directory" means an initial directory
record in certain directory.
[0047] At step S34, it is checked whether the above file
information is an MP3 file. Here, file identifier information
within the directory record is referred, thereby determining
whether an extender is an "MP3". If it is an MP3 file, the process
goes to step S35. if it is not an MP3 file, the process goes to
step S38.
[0048] At step S35, it is checked whether a song counter is "99" or
lower. This is because Red Book (which is a standard of CD)
requires that one CD contain 99 or fewer songs. If the song counter
indicates a number of "99" or less, TOC data is prepared at step
S36. On the other hand, it the number is "100" or more, the process
is ended. Specifically, TOC data can be prepared at step S36, in
accordance with a flowchart shown in FIG. 4.
[0049] Namely, at first, it is required to detect the position of
an extent within the directory record, i.e., LBN of front head of
unit information managed by the directory record, and to convert a
value of the position of the extent into a time value, with one
second serving as 75 frames (step S361 and step S362). Then, two
seconds are added in the calculated time value (a similar practice
when authoring is performed on a video tape), thereby producing TOC
data by registering the time value as an absolute time (steps S363,
S364).
[0050] Namely, since the sub-code frame size of CD is the same as
the block size of CD-ROM, if LBN (position of extent) of certain
point within CD-ROM is used as the number of sub-code frames and
converted into a time value (in which two seconds are then added),
it is possible to obtain an absolute time extending from the inmost
circumference of CD.
[0051] Some detailed examples of conversion into the TOC data will
be described below by explaining a directory record within ISO9660
file shown in FIG. 6. Here, the position of an extent is acquired,
and this is used as the number of sub-code frames of CD and two
seconds are converted into a total frame time, followed by adding
the above data ("0000254B" h) in the total frame time.
[0052] In other words, since one second can cover 75 frames, the
total frame time of two seconds can cover "96" h frames. Therefore,
"254B" h+"96" h becomes a"251E1" h frames. When this is converted
into a time unit (hour, minute, second), it will become "25E1"
h/75=129+22, thereby becoming 2 minutes and 9 seconds and 22
frames. This data is than stored in the TOC area.
[0053] Referring again to FIG. 3, at step S37, the song counter is
increased by 1. Then, at step S38, a next directory record is
obtained. In fact, such a next directory record is obtained from a
directory record group read-in at step S36. The position of the
next directory record can be known from the length information of
the directory record inside the present directory record.
[0054] Then, at step S39, it is checked whether the position of the
directory record is the front head of a sector. In fact, this can
be known from the present address information, in the form of "1
sector/2048 byte. If it is the front head of a sector, the process
is ended. If not, directory record group of a next sector is
read-in (step S40).
[0055] However, information of one directory record group isn't
always within one sector. If information of one directory record
group can not be received within one sector, continued information
can be stored in a next sector. But, ISO9660 format fails to record
information of one directory record over boundaries between
sectors.
[0056] Therefore, as shown in FIG. 5, there is a directory record B
in connection with a directory record A recorded in sector N. After
directory record A is recorded, if a vacant capacity (hatched
portion) of sector N is smaller than the length of directory record
B, the directory record B will be recorded in an area starting from
the front head of sector N+1.
[0057] If it is determined at step S31 that there is no directory
record, for example, at a time a directory data next to directory
record A (shown in FIG. 5) is about to be obtained, and if this
position at this time is not a front head of a sector, it is
allowed to assume that there is a next directory record. If, at
step S39 it is determined that this is not a front head of a
sector, an operation at step S40 will read-in a directory record
group of a next sector.
[0058] On the other hand, if it is determined at the step S39 that
the position of the directory record at this time is the front head
of a sector, since there is no directory record existing at the
front head of the sector, it is determined that there is no
director record next to a final directory record of a former
sector, so that the process is ended.
[0059] At step S33 it is determined whether information of a
directory record is "its own directory". If it is determined that a
directory record is "its own directory", this will be an initial
directory record in the directory. At this time, it is determined
at step S39 whether the position of the directory record at this
time is a front head of a sector. If an answer is YES, it is
allowed to determine that information of other albums has started
in a manner shown in FIG. 5.
[0060] Although it has been described in the above that ISO9660
format data may be converted into TOC information of CD, (i.e.,
converted into absolute time information), the present invention
should not be limited to this specific example. In other words, the
present invention can be realized in any other embodiments,
provided that the position of unit information managed under
hierarchical structure can be converted into absolute time.
[0061] As described in the above, according to the present
invention, if TOC data is generated from the information of the
path table and if the data recorded in a format different from CD
is reproduced in accordance with the TOC data, it is possible to
perform program reproduction and repeat reproduction, allowing the
use of software contained within a conventional CD player (without
having to modify the software to any extent), thus providing a user
with a convenience as if he or she is using a conventional CD.
[0062] Therefore, when preparing a software for controlling the
operation of the reproducing apparatus, it is not necessary to
prepare (in accordance with a path table) other software for
carrying out song searching, thereby alleviating a burden on
software maker. Further, when reproducing MP3 data recorded in a
format different from CD (for example, recorded in accordance with
ISO9660 standard), and when there is an instruction for searching a
song, it is not necessary to store a path table, nor is it needed
to read-in a path table, thereby permitting a high operational
speed for the information reproducing apparatus While the invention
has been described in conjunction with preferred specific
embodiment thereof, it will be understood that this description is
intended to illustrate and not limit the scope of the invention,
which is defined by the following claims.
* * * * *